This invention relates generally to methods and apparatus for monitoring a person.
According to the National Center for Health Statistics Monitoring Health Care in America. Quarterly Fact Sheet. September 1996, cerebrovascular disease is the third leading cause of death in America, accounting for over 154,000 deaths in 1994. This fact is true despite death rates from stroke having actually dropped nearly every year since 1950. In 1993, 109 years of potential life were lost due to stroke for every 100,000 persons under age 65. Stroke is the third leading cause of death for all people age 45 and over. In 1993 the national death rate from stroke was 26.5 deaths per 100,000 population. During the period 1990-92, age-adjusted death rates by State ranged from 20.8 for Rhode Island to 40.0 for South Carolina. Regionally, cerebrovascular disease mortality is highest for Indiana and what is referred to as the “stroke belt,” the southeastern states of Louisiana, Mississippi, Alabama, Georgia, North Carolina, South Carolina, Virginia, Tennessee, Kentucky, and Arkansas. The lowest rates are in Colorado, New Mexico, Arizona, Nebraska, Iowa, and Florida, as well as the northeastern states of Maine, Vermont, New York, Massachusetts, Connecticut, and Rhode Island. According to 1994 data, nearly 3 million Americans have suffered strokes at some point, or 1 per 100 population. Five percent of males aged 65 and over and 6 percent of women in the same age group have suffered a stroke.
A stroke occurs when a blood vessel (artery) that supplies blood to the brain bursts or is blocked by a blood clot. Within minutes, the nerve cells in that area of the brain are damaged, and they may die within a few hours. As a result, the part of the body controlled by the damaged section of the brain cannot function properly. An ischemic stroke is caused by a reduction in blood flow to the brain. This can be caused by a blockage or narrowing in an artery that supplies blood to the brain or when the blood flow is reduced because of a heart or other condition. A hemorrhagic stroke develops when an artery in the brain leaks or bursts and causes bleeding inside the brain tissue or near the surface of the brain. Prior to a stroke, a person may have one or more transient ischemic attacks (TIAs), which are a warning signal that a stroke may soon occur. TIAs are often called mini strokes because their symptoms are similar to those of a stroke. However, unlike stroke symptoms, TIA symptoms usually disappear within 10 to 20 minutes, although they may last up to 24 hours. Symptoms of a stroke begin suddenly and may include: numbness, weakness, or paralysis of the face, arm, or leg, especially on one side of the body; vision problems in one or both eyes, such as double vision or loss of vision; confusion, trouble speaking or understanding; trouble walking, dizziness, loss of balance or coordination, or severe headache.